Ulmaceae


The Ulmaceae are a family of flowering plant that includes the elms, and the zelkovas. Members of the family are widely distributed throughout the north temperate zone, and have a scattered distribution elsewhere except for Australasia.
The family was formerly sometimes treated to include the hackberries,, but analysis by the Angiosperm Phylogeny Group members suggests that these genera are better placed in the related family Cannabaceae. The circumscription included in the taxobox is the one suggested by P. Stevens on his Missouri Botanical Garden Angiosperm Phylogeny Website and includes information from the Royal Botanic Gardens, Kew Vascular Plant Families and Genera list. It generally is considered to include ca 7 genera and about 45 species. Some classifications also include the genus Ampelocera.

Description

The family is a group of evergreen or deciduous trees and shrubs with mucilaginous substances in leaf and bark tissue. Leaves are usually alternate on the stems. The leaf blades are simple, with entire or variously toothed margins, and often have an asymmetrical base. The flowers are small and either bisexual or unisexual. The fruit is an indehiscent samara, nut, or drupe. Ulmus provides important timber trees mostly for furniture, and U. rubra, the slippery elm, is a medicinal plant known for the demulcent property of its inner bark. Planera aquatica is also a timber species. Planera, Ulmus, and Zelkova are all grown as ornamental trees.

Phylogeny

Modern molecular phylogenetics suggest the following relationships: